As an Internet user environment has advanced, an image production field, which had been the province of specialists, has become increasingly common. A variety of internet sites which share video files based on the Internet are provided where users may upload, post, and share their video files.
There are a great variety of methods for producing videos, e.g., a method using high-priced technical equipment and a simple method using a smart phone. The video which is directly produced by a personal user is called a user created content (UCC) video. Personal users' desires to produce videos and expression methods are increasing, and the personal users' desires to express UCC video through image synthesis are also increasing.
A chroma-key synthesis scheme for video synthesis is a method in which a video is captured in a green or blue screen area, and a screen image is removed, and then another background is synthesized. High-priced technical equipment and skilled techniques for dealing with the equipment are required to synthesize two videos using the chroma-key synthesis scheme. Therefore, it is difficult for nonprofessional personal users in a video synthesis field to produce the UCC video through the video synthesis.
Meanwhile, a video file for individual use may be leaked online despite a user's intention, and thus personal privacy may be infringed. As an internet environment is generalized, personal privacy infringement comes to the fore as a serious social problem. Therefore, in the case of the personal UCC video produced in public places, it is necessary to prevent the UCC video from being leaked in despite the user's intention, thereby protecting the personal privacy.